Granite Comes in all sorts of colors for your kitchen countertops, but they all have one thing in common. They need to be sealed and taken care of or else your granite will become stained and mottled. Most home improvement stores sell granite sealant. This product will absorb into the stone and provide a layer of stain resistance that will last anywhere from 6 to 12 months. But, it is imperative that you remember to reseal the stone yearly to keep it looking new. One of the most frequent problems we see with granite stains is around the sink area where homeowners use harsh chemicals in the sink and neglect to keep the stone properly sealed.